Monday 14 July 2014 12.02 EDT
First published on Monday 14 July 2014 12.02 EDT

What if instead of Buy Buy Footsie, it was Buy Buy Scotsie?

As the vote on independence approaches, a report shows that a notional index of 100 Scottish companies currently listed on the London Stock Exchange would have grown by 5.7% in real terms (with dividends reinvested) since 1955.

But it would have been outperformed by stocks from the rest of the UK, which rose 6.8% over the same period. The difference is due to the predominance of financial companies in the "Scotsie 100", and in particular the near collapse of Royal Bank of Scotland and HBOS in the banking crisis. Without this, it would have outperformed the UK index by a small margin.

The report, by the London Business School and consultancy Walbrook Economics, uses the location of a company's headquarters to judge whether it is Scottish or not. Apart from financial companies such as banks and investment trusts, the Scotsie index is dominated by utilities, and oil and gas companies. The largest are energy business SSE, insurer Standard Life, Royal Bank of Scotland, FTSE100 engineer Weir Group and Aggreko, the generator manufacturer.

The research was driven by the question of whether Scotland should set up its own stock exchange – something which existed until 1973 – as other countries have done after gaining independence. If all Scotsie 100 stocks chose to list on a new Scottish bourse, it would rank 28th in the world. This, says the report, is the same as the Scottish football team's post-World Cup Fifa ranking.

But the report concludes: "It will be a tough challenge to attract the Scotsie 100 companies away from the large liquid international London exchange on which they are already listed along with their FTSE imprimatur. It would make more sense for Scotland to continue to rely for its stock market services on the LSE and AIM."

Paul Marsh, of London Business School, said there was uncertainty over the terms of separating from the UK in the event of a yes vote in the 18 September referendum. But he added: "We believe that investors in Scotsie 100 stocks should not be unduly concerned, nor should they be making contingency plans to rebalance their portfolios.

"To some extent, they are protected by the fact that both companies and individuals can re-domicile if necessary. There would also be a period of at least 18 months during which the terms of separation are negotiated. They can afford to wait and see."